Mosby's 2014 Nursing Drug Reference (12 page)
Read Mosby's 2014 Nursing Drug Reference Online
Authors: Linda Skidmore-Roth
Diuretics are divided into subgroups: thiazides and thiazide-like diuretics, loop diuretics, carbonic anhydrase inhibitors, osmotic diuretics, and potassium-sparing diuretics. Each one of these subgroups has its own mechanism of action. Thiazides and thiazide-like diuretics increase excretion of water and sodium by inhibiting resorption in the early distal tubule. Loop diuretics inhibit resorption of sodium and chloride in the thick ascending limb of the loop of Henle. Carbonic anhydrase inhibitors increase sodium excretion by decreasing sodium-hydrogen ion exchange throughout the renal tubule. Carbonic anhydrase inhibitors also decrease secretion of aqueous humor in the eye and thus decrease intraocular pressure. Osmotic diuretics increase the osmotic pressure of glomerular filtrate, thus decreasing net absorption of sodium. The potassium-sparing diuretics interfere with sodium resorption at the distal tubule, thus decreasing potassium excretion.
B/P is reduced in hypertension; edema is reduced in congestive heart failure; intraocular pressure is decreased in glaucoma.
Persons with electrolyte imbalances (Na, Cl, K), dehydration, or anuria should not be given these products until the problem is corrected.
Precautions:
Caution must be used when diuretics are given to geriatric patients; electrolyte disturbances and dehydration can occur rapidly. Hepatic/renal disease may cause poor metabolism and excretion of the product.
•
In
AM
to avoid interference with sleep if using product as a diuretic
•
Potassium replacement if potassium is <3 mg/dl
Hypokalemia, hyperuricemia, and hyperglycemia occur most frequently with thiazide diuretics. Aplastic anemia, blood dyscrasias, volume depletion, and dehydration may occur when thiazide-like diuretics, loop diuretics, or carbonic anhydrase inhibitors are given. Side effects and adverse reactions vary widely for the miscellaneous products.
Onset, peak, and duration vary widely among the different subgroups of these products.
Cholestyramine and colestipol will decrease the absorption of thiazide diuretics. Concurrent use of thiazides with diazoxide may increase hyperuricemia, hyperglycemia, and antihypertensive effects of thiazides. Ototoxicity may occur when loop diuretics are used with aminoglycosides. Thiazide and loop diuretics may increase therapeutic and toxic effects of lithium.
•
Decreased cardiac output
[adverse reactions]
•
Excess fluid volume
[uses]
•
Weight, I&O daily to determine fluid loss; check skin turgor for dehydration
•
Electrolytes: K, Na, Cl; include BUN, blood glucose, CBC, serum creatinine, blood pH, ABGs, uric acid, Ca; electrolyte imbalances may occur quickly
•
B/P (lying and standing); postural hypotension may occur because fluid loss occurs first from intravascular spaces
•
Signs of metabolic alkalosis, including drowsiness and restlessness
•
Signs of hypokalemia with some products: postural hypotension, malaise, fatigue, tachycardia, leg cramps, weakness
•
Therapeutic response: improvement in edema of feet, legs, sacral area daily if medication is being used in congestive heart failure; improvement in B/P if medication is being used as a diuretic; improvement in intraocular pressure if medication is being used to decrease aqueous humor in the eye
•
To take product early in the day (diuretic) to prevent nocturia
2
ANTAGONISTS
Histamine H
2
antagonists act by inhibiting histamine at the H
2
-receptor site in parietal cells, which inhibits gastric acid secretion.
Histamine H
2
antagonists are used for short-term treatment of duodenal and gastric ulcers and maintenance therapy for duodenal ulcer; gastroesophageal reflux disease.
Persons with hypersensitivity should not use these products.
Precautions:
Caution should be used in pregnancy, breastfeeding, child <16 yr, organic brain syndrome, hepatic/renal disease.
•
With meals for prolonged product effect
•
Antacids 1 hr before or 1 hr after cimetidine
•
IV slowly; bradycardia may occur; give over 30 min
The most serious adverse reactions are agranulocytosis, thrombocytopenia, neutropenia, aplastic anemia, and exfoliative dermatitis. The most common side effects are confusion (not with ranitidine), headache, and diarrhea.
Onset, peak, and duration vary widely among products. Most products are metabolized in the liver and excreted in urine.
Antacids interfere with absorption of histamine H
2
antagonists. Check individual monographs for specific information.
•
Risk for injury
[bleeding]
•
Deficient knowledge
[teaching]
•
Chronic pain
[uses]
•
Gastric pH (>5 should be maintained)
•
I&O ratio, BUN, creatinine
•
Storage of diluted sol at room temperature for up to 48 hr
•
Therapeutic response: decreased pain in abdomen
•
That gynecomastia, impotence may occur but are reversible
•
To avoid driving, other hazardous activities until patient is stabilized on this medication
•
To avoid black pepper, caffeine, alcohol, harsh spices, extremes in temperature of food
•
To avoid OTC preparations: aspirin, cough, cold preparations
•
That product must be continued for prescribed time to be effective
•
To report bruising, fatigue, malaise; blood dyscrasias may occur
Immunosuppressants act by inhibiting lymphocytes (T).
Most immunosuppressants are used for organ transplants to prevent rejection.
Products are contraindicated in hypersensitivity.
Precautions:
Caution should be used in severe renal/hepatic disease and pregnancy.
•
For several days before transplant surgery
•
With meals for GI upset or product mixed with chocolate milk
•
With oral antifungal for
Candida
infections
The most serious adverse reactions are albuminuria, hematuria, proteinuria, renal failure, and hepatotoxicity. The most common side effects are overgrowth of oral
Candida
, gum hyperplasia, tremors, and headache. The most serious adverse reactions for azathioprine are hematologic (leukopenia and thrombocytopenia) and GI (nausea and vomiting). There is a risk of secondary infection.
Onset, peak, and duration vary widely among products. Most products are metabolized in the liver and excreted in urine.
Interactions vary widely among products. Check individual monographs for specific information.
•
Risk for infection
[adverse reactions]
•
Risk for injury
[uses]
•
Deficient knowledge
[teaching]
•
Renal studies: BUN, creatinine at least monthly during treatment, 3 mo after treatment
•
Hepatic studies: alk phos, AST (SGOT), ALT (SGPT), bilirubin
•
Product blood levels during treatment
•
Hepatotoxicity: dark urine, jaundice, itching, light-colored stools; product should be discontinued
•
Therapeutic response: absence of rejection
•
To report fever, chills, sore throat, fatigue; serious infections may occur
•
To use contraceptive measures during treatment and for 12 wk after ending therapy
Laxatives are divided into bulk products, lubricants, osmotics, saline laxative stimulants, and stool softeners. Bulk laxatives work by absorbing water and expanding to increase moisture content and bulk in the stool. Lubricants increase water retention in the stool, causing reabsorption of water in the bowel. Osmotics increase distention and promote peristalsis. Saline draws water into the intestinal lumen. Stimulants act by increasing peristalsis by direct effect on the intestine. Stool softeners reduce surface tension of liquids of the bowel.
Laxatives are used as a preparation for bowel and rectal exam, constipation, and stool softener.
Persons with GI obstruction, perforation, gastric retention, toxic colitis, megacolon, abdominal pain, nausea, vomiting, or fecal impaction should not use these products.
Precautions:
Caution should be used in rectal bleeding, large hemorrhoids, and anal excoriation.
•
Swallow tabs whole; do not break, crush, or chew
•
Alone only with water for better absorption; do not take within 1 hr of antacids, milk, or cimetidine
The most common side effects are nausea, abdominal cramps, and diarrhea.
Onset, peak, and duration vary among products.
Interactions vary widely among products. Check individual monographs for specific information.
•
Constipation
[uses]
•
Diarrhea
[adverse reactions]
•
Deficient knowledge
[teaching]
•
Blood, urine electrolytes if product is used often by patient
•
I&O ratio to identify fluid loss
•
Cause of constipation: identify whether fluids, bulk, or exercise missing from lifestyle
•
Cramping, rectal bleeding, nausea, vomiting; if these symptoms occur, product should be discontinued
•
Therapeutic response: decrease in constipation
•
Not to use laxatives for long-term therapy; bowel tone will be lost
•
That normal bowel movements do not always occur daily
•
Not to use in presence of abdominal pain, nausea, vomiting
•
To notify prescriber of abdominal pain, nausea, vomiting
•
To notify prescriber if constipation is unrelieved or if symptoms of electrolyte imbalance: muscle cramps, pain, weakness, dizziness
Neuromuscular blocking agents are divided into depolarizing and nondepolarizing blockers. They act by inhibiting transmission of nerve impulses by binding with cholinergic receptor sites.
Neuromuscular blocking agents are used to facilitate endotracheal intubation and skeletal muscle relaxation during mechanical ventilation, surgery, or general anesthesia.
Persons who are hypersensitive should not be given this product.
Precautions:
Caution should be used in pregnancy, thyroid disease, collagen disease, cardiac disease, breastfeeding, children <2 yr, electrolyte imbalances, dehydration, neuromuscular disease (myasthenia gravis), and respiratory disease.
•
Using nerve stimulator by anesthesia provider to determine neuromuscular blockade
•
Anticholinesterase to reverse neuromuscular blockade
•
IV undiluted over 1-2 min (only by qualified person, usually an anesthesiologist)
The most serious adverse reactions are prolonged apnea, bronchospasm, cyanosis, respiratory depression, and malignant hyperthermia. The most common side effects are bradycardia and decreased motility.
Onset, peak, and duration vary widely among products. Most products are metabolized in the liver and excreted in urine.
Aminoglycosides potentiate neuromuscular blockade. Check individual monographs for specific information.
•
Risk for injury
[adverse reactions]
•
Deficient knowledge
[teaching]
•
For electrolyte imbalances (K, Mg); may lead to increased action of this product
•
VS (B/P, pulse, respirations, airway) q15min until fully recovered; rate, depth,
pattern of respirations, strength of hand grip
•
I&O ratio; check for urinary retention, frequency, hesitancy
•
Recovery: decreased paralysis of face, diaphragm, leg, arm, rest of body
•
Allergic reactions: rash, fever, respiratory distress, pruritus; product should be discontinued
•
Storage in light-resistant container, cool area
•
Reassurance if communication is difficult during recovery from neuromuscular blockade
•
Therapeutic response: paralysis of jaw, eyelid, head, neck, rest of body